104 goto mem1;
105
106 /* Allocate/initialize root's parent. */
107 if ((parent = fts_alloc(sp, "", 0)) == NULL)
108 goto mem2;
109 parent->fts_level = FTS_ROOTPARENTLEVEL;
110
111 /* Allocate/initialize root(s). */
112 for (root = NULL, nitems = 0; *argv; ++argv, ++nitems) {
113 /* Don't allow zero-length paths. */
114 if ((len = strlen(*argv)) == 0) {
115 errno = ENOENT;
116 goto mem3;
117 }
118
119 if ((p = fts_alloc(sp, *argv, len)) == NULL)
120 goto mem3;
121 p->fts_level = FTS_ROOTLEVEL;
122 p->fts_parent = parent;
123 p->fts_accpath = p->fts_name;
124 p->fts_info = fts_stat(sp, p);
125
126 /* Command-line "." and ".." are real directories. */
127 if (p->fts_info == FTS_DOT)
128 p->fts_info = FTS_D;
129
130 p->fts_link = NULL;
131 if (root == NULL)
132 tmp = root = p;
133 else {
134 tmp->fts_link = p;
135 tmp = p;
136 }
137 }
138
139 /*
140 * Allocate a dummy pointer and make fts_read think that we've just
141 * finished the node before the root(s); set p->fts_info to FTS_INIT
142 * so that everything about the "current" node is ignored.
143 */
144 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL)
145 goto mem3;
146 sp->fts_cur->fts_link = root;
147 sp->fts_cur->fts_info = FTS_INIT;
148
149 /*
150 * If using chdir(2), grab a file descriptor pointing to dot to ensure
151 * that we can get back here; this could be avoided for some paths,
152 * but almost certainly not worth the effort. Slashes, symbolic links,
153 * and ".." are all fairly nasty problems. Note, if we can't get the
154 * descriptor we run anyway, just more slowly.
155 */
156 if (!ISSET(FTS_NOCHDIR) &&
157 (sp->fts_rfd = open(".", O_RDONLY | O_CLOEXEC)) < 0)
158 SET(FTS_NOCHDIR);
159
160 if (nitems == 0)
161 free(parent);
162
163 return (sp);
164
165mem3: fts_lfree(root);
166 free(parent);
167mem2: free(sp->fts_path);
168mem1: free(sp);
169 return (NULL);
170}
171
172static void
173fts_load(FTS *sp, FTSENT *p)
174{
175 size_t len;
176 char *cp;
177
178 /*
179 * Load the stream structure for the next traversal. Since we don't
180 * actually enter the directory until after the preorder visit, set
181 * the fts_accpath field specially so the chdir gets done to the right
182 * place and the user can access the first node. From fts_open it's
183 * known that the path will fit.
184 */
185 len = p->fts_pathlen = p->fts_namelen;
186 memmove(sp->fts_path, p->fts_name, len + 1);
187 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) {
188 len = strlen(++cp);
189 memmove(p->fts_name, cp, len + 1);
190 p->fts_namelen = len;
191 }
192 p->fts_accpath = p->fts_path = sp->fts_path;
193 sp->fts_dev = p->fts_dev;
194}
195
196int
197fts_close(FTS *sp)
198{
199 FTSENT *freep, *p;
200 int rfd, error = 0;
201
202 /*
203 * This still works if we haven't read anything -- the dummy structure
204 * points to the root list, so we step through to the end of the root
205 * list which has a valid parent pointer.
206 */
207 if (sp->fts_cur) {
208 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) {
209 freep = p;
210 p = p->fts_link ? p->fts_link : p->fts_parent;
211 free(freep);
212 }
213 free(p);
214 }
215
216 /* Stash the original directory fd if needed. */
217 rfd = ISSET(FTS_NOCHDIR) ? -1 : sp->fts_rfd;
218
219 /* Free up child linked list, sort array, path buffer, stream ptr.*/
220 if (sp->fts_child)
221 fts_lfree(sp->fts_child);
222 free(sp->fts_path);
223 free(sp);
224
225 /* Return to original directory, checking for error. */
226 if (rfd != -1) {
227 int saved_errno;
228 error = fchdir(rfd);
229 saved_errno = errno;
230 (void)close(rfd);
231 errno = saved_errno;
232 }
233
234 return (error);
235}
236
237/*
238 * Special case of "/" at the end of the path so that slashes aren't
239 * appended which would cause paths to be written as "....//foo".
240 */
241#define NAPPEND(p) \
242 (p->fts_path[p->fts_pathlen - 1] == '/' \
243 ? p->fts_pathlen - 1 : p->fts_pathlen)
244
245FTSENT *
246fts_read(FTS *sp)
247{
248 FTSENT *p, *tmp;
249 int instr;
250 char *t;
251
252 /* If finished or unrecoverable error, return NULL. */
253 if (sp->fts_cur == NULL || ISSET(FTS_STOP))
254 return (NULL);
255
256 /* Set current node pointer. */
257 p = sp->fts_cur;
258
259 /* Save and zero out user instructions. */
260 instr = p->fts_instr;
261 p->fts_instr = FTS_NOINSTR;
262
263 /* Directory in pre-order. */
264 if (p->fts_info == FTS_D) {
265 /* If skipped or crossed mount point, do post-order visit. */
266 if (instr == FTS_SKIP ||
267 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) {
268 if (sp->fts_child) {
269 fts_lfree(sp->fts_child);
270 sp->fts_child = NULL;
271 }
272 p->fts_info = FTS_DP;
273 return (p);
274 }
275
276 /*
277 * Cd to the subdirectory.
278 *
279 * If have already read and now fail to chdir, whack the list
280 * to make the names come out right, and set the parent errno
281 * so the application will eventually get an error condition.
282 * Set the FTS_DONTCHDIR flag so that when we logically change
283 * directories back to the parent we don't do a chdir.
284 *
285 * If haven't read do so. If the read fails, fts_build sets
286 * FTS_STOP or the fts_info field of the node.
287 */
288 if (sp->fts_child) {
289 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) {
290 p->fts_errno = errno;
291 p->fts_flags |= FTS_DONTCHDIR;
292 for (p = sp->fts_child; p; p = p->fts_link)
293 p->fts_accpath =
294 p->fts_parent->fts_accpath;
295 }
296 } else if ((sp->fts_child = fts_build(sp)) == NULL) {
297 if (ISSET(FTS_STOP))
298 return (NULL);
299 return (p);
300 }
301 p = sp->fts_child;
302 sp->fts_child = NULL;
303 goto name;
304 }
305
306 /* Move to the next node on this level. */
307next: tmp = p;
308 if ((p = p->fts_link)) {
309 free(tmp);
310
311 /*
312 * If reached the top, return to the original directory (or
313 * the root of the tree), and load the paths for the next root.
314 */
315 if (p->fts_level == FTS_ROOTLEVEL) {
316 if (FCHDIR(sp, sp->fts_rfd)) {
317 SET(FTS_STOP);
318 return (NULL);
319 }
320 fts_load(sp, p);
321 return (sp->fts_cur = p);
322 }
323
324 /*
325 * User may have called fts_set on the node. If skipped,
326 * ignore. If followed, get a file descriptor so we can
327 * get back if necessary.
328 */
329 if (p->fts_instr == FTS_SKIP)
330 goto next;
331
332name: t = sp->fts_path + NAPPEND(p->fts_parent);
333 *t++ = '/';
334 memmove(t, p->fts_name, p->fts_namelen + 1);
335 return (sp->fts_cur = p);
336 }
337
338 /* Move up to the parent node. */
339 p = tmp->fts_parent;
340 free(tmp);
341
342 if (p->fts_level == FTS_ROOTPARENTLEVEL) {
343 /*
344 * Done; free everything up and set errno to 0 so the user
345 * can distinguish between error and EOF.
346 */
347 free(p);
348 errno = 0;
349 return (sp->fts_cur = NULL);
350 }
351
352 /* NUL terminate the pathname. */
353 sp->fts_path[p->fts_pathlen] = '\0';
354
355 /*
356 * Return to the parent directory. If at a root node or came through
357 * a symlink, go back through the file descriptor. Otherwise, cd up
358 * one directory.
359 */
360 if (p->fts_level == FTS_ROOTLEVEL) {
361 if (FCHDIR(sp, sp->fts_rfd)) {
362 SET(FTS_STOP);
363 sp->fts_cur = p;
364 return (NULL);
365 }
366 } else if (!(p->fts_flags & FTS_DONTCHDIR) &&
367 fts_safe_changedir(sp, p->fts_parent, -1, "..")) {
368 SET(FTS_STOP);
369 sp->fts_cur = p;
370 return (NULL);
371 }
372 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;
373 return (sp->fts_cur = p);
374}
375
376/*
377 * Fts_set takes the stream as an argument although it's not used in this
378 * implementation; it would be necessary if anyone wanted to add global
379 * semantics to fts using fts_set. An error return is allowed for similar
380 * reasons.
381 */
382/* ARGSUSED */
383int
384fts_set(FTS *sp, FTSENT *p, int instr)
385{
386 if (instr && instr != FTS_NOINSTR && instr != FTS_SKIP) {
387 errno = EINVAL;
388 return (1);
389 }
390 p->fts_instr = instr;
391 return (0);
392}
393
394/*
395 * This is the tricky part -- do not casually change *anything* in here. The
396 * idea is to build the linked list of entries that are used by fts_children
397 * and fts_read. There are lots of special cases.
398 *
399 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is
400 * set and it's a physical walk (so that symbolic links can't be directories),
401 * we can do things quickly. First, if it's a 4.4BSD file system, the type
402 * of the file is in the directory entry. Otherwise, we assume that the number
403 * of subdirectories in a node is equal to the number of links to the parent.
404 * The former skips all stat calls. The latter skips stat calls in any leaf
405 * directories and for any files after the subdirectories in the directory have
406 * been found, cutting the stat calls by about 2/3.
407 */
408static FTSENT *
409fts_build(FTS *sp)
410{
411 struct dirent *dp;
412 FTSENT *p, *head;
413 FTSENT *cur, *tail;
414 DIR *dirp;
415 void *oldaddr;
416 size_t dlen, len, maxlen;
417 int nitems, cderrno, descend, level, doadjust;
418 int saved_errno;
419 char *cp;
420
421 /* Set current node pointer. */
422 cur = sp->fts_cur;
423
424 /*
425 * Open the directory for reading. If this fails, we're done.
426 * If being called from fts_read, set the fts_info field.
427 */
428 if ((dirp = opendir(cur->fts_accpath)) == NULL) {
429 cur->fts_info = FTS_DNR;
430 cur->fts_errno = errno;
431 return (NULL);
432 }
433
434 /*
435 * If we're going to need to stat anything or we want to descend
436 * and stay in the directory, chdir. If this fails we keep going,
437 * but set a flag so we don't chdir after the post-order visit.
438 * We won't be able to stat anything, but we can still return the
439 * names themselves. Note, that since fts_read won't be able to
440 * chdir into the directory, it will have to return different path
441 * names than before, i.e. "a/b" instead of "b". Since the node
442 * has already been visited in pre-order, have to wait until the
443 * post-order visit to return the error. There is a special case
444 * here, if there was nothing to stat then it's not an error to
445 * not be able to stat. This is all fairly nasty. If a program
446 * needed sorted entries or stat information, they had better be
447 * checking FTS_NS on the returned nodes.
448 */
449 cderrno = 0;
450 if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) {
451 cur->fts_errno = errno;
452 cur->fts_flags |= FTS_DONTCHDIR;
453 descend = 0;
454 cderrno = errno;
455 (void)closedir(dirp);
456 dirp = NULL;
457 } else
458 descend = 1;
459
460 /*
461 * Figure out the max file name length that can be stored in the
462 * current path -- the inner loop allocates more path as necessary.
463 * We really wouldn't have to do the maxlen calculations here, we
464 * could do them in fts_read before returning the path, but it's a
465 * lot easier here since the length is part of the dirent structure.
466 *
467 * If not changing directories set a pointer so that can just append
468 * each new name into the path.
469 */
470 len = NAPPEND(cur);
471 if (ISSET(FTS_NOCHDIR)) {
472 cp = sp->fts_path + len;
473 *cp++ = '/';
474 }
475 len++;
476 maxlen = sp->fts_pathlen - len;
477
478 /*
479 * fts_level is signed so we must prevent it from wrapping
480 * around to FTS_ROOTLEVEL and FTS_ROOTPARENTLEVEL.
481 */
482 level = cur->fts_level;
483 if (level < FTS_MAXLEVEL)
484 level++;
485
486 /* Read the directory, attaching each entry to the `link' pointer. */
487 doadjust = 0;
488 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) {
489 if (ISDOT(dp->d_name))
490 continue;
491
492#if HAVE_DIRENT_NAMLEN
493 dlen = dp->d_namlen;
494#else
495 dlen = strlen(dp->d_name);
496#endif
497
498 if (!(p = fts_alloc(sp, dp->d_name, dlen)))
499 goto mem1;
500 if (dlen >= maxlen) { /* include space for NUL */
501 oldaddr = sp->fts_path;
502 if (fts_palloc(sp, dlen + len + 1)) {
503 /*
504 * No more memory for path or structures. Save
505 * errno, free up the current structure and the
506 * structures already allocated.
507 */
508mem1: saved_errno = errno;
509 if (p)
510 free(p);
511 fts_lfree(head);
512 (void)closedir(dirp);
513 cur->fts_info = FTS_ERR;
514 SET(FTS_STOP);
515 errno = saved_errno;
516 return (NULL);
517 }
518 /* Did realloc() change the pointer? */
519 if (oldaddr != sp->fts_path) {
520 doadjust = 1;
521 if (ISSET(FTS_NOCHDIR))
522 cp = sp->fts_path + len;
523 }
524 maxlen = sp->fts_pathlen - len;
525 }
526
527 p->fts_level = level;
528 p->fts_parent = sp->fts_cur;
529 p->fts_pathlen = len + dlen;
530 if (p->fts_pathlen < len) {
531 /*
532 * If we wrap, free up the current structure and
533 * the structures already allocated, then error
534 * out with ENAMETOOLONG.
535 */
536 free(p);
537 fts_lfree(head);
538 (void)closedir(dirp);
539 cur->fts_info = FTS_ERR;
540 SET(FTS_STOP);
541 errno = ENAMETOOLONG;
542 return (NULL);
543 }
544
545 if (cderrno) {
546 p->fts_info = FTS_NS;
547 p->fts_errno = cderrno;
548 p->fts_accpath = cur->fts_accpath;
549 } else {
550 /* Build a file name for fts_stat to stat. */
551 if (ISSET(FTS_NOCHDIR)) {
552 p->fts_accpath = p->fts_path;
553 memmove(cp, p->fts_name, p->fts_namelen + 1);
554 } else
555 p->fts_accpath = p->fts_name;
556 /* Stat it. */
557 p->fts_info = fts_stat(sp, p);
558 }
559
560 /* We walk in directory order so "ls -f" doesn't get upset. */
561 p->fts_link = NULL;
562 if (head == NULL)
563 head = tail = p;
564 else {
565 tail->fts_link = p;
566 tail = p;
567 }
568 ++nitems;
569 }
570 if (dirp)
571 (void)closedir(dirp);
572
573 /*
574 * If realloc() changed the address of the path, adjust the
575 * addresses for the rest of the tree and the dir list.
576 */
577 if (doadjust)
578 fts_padjust(sp, head);
579
580 /*
581 * If not changing directories, reset the path back to original
582 * state.
583 */
584 if (ISSET(FTS_NOCHDIR)) {
585 if (len == sp->fts_pathlen || nitems == 0)
586 --cp;
587 *cp = '\0';
588 }
589
590 /*
591 * If descended after called from fts_children or after called from
592 * fts_read and nothing found, get back. At the root level we use
593 * the saved fd; if one of fts_open()'s arguments is a relative path
594 * to an empty directory, we wind up here with no other way back. If
595 * can't get back, we're done.
596 */
597 if (descend && !nitems &&
598 (cur->fts_level == FTS_ROOTLEVEL ? FCHDIR(sp, sp->fts_rfd) :
599 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) {
600 cur->fts_info = FTS_ERR;
601 SET(FTS_STOP);
602 return (NULL);
603 }
604
605 /* If didn't find anything, return NULL. */
606 if (!nitems) {
607 cur->fts_info = FTS_DP;
608 return (NULL);
609 }
610 return (head);
611}
612
613static unsigned short
614fts_stat(FTS *sp, FTSENT *p)
615{
616 FTSENT *t;
617 dev_t dev;
618 ino_t ino;
619 struct stat *sbp;
620
621 /* If user needs stat info, stat buffer already allocated. */
622 sbp = p->fts_statp;
623
624 if (lstat(p->fts_accpath, sbp)) {
625 p->fts_errno = errno;
626 memset(sbp, 0, sizeof(struct stat));
627 return (FTS_NS);
628 }
629
630 if (S_ISDIR(sbp->st_mode)) {
631 /*
632 * Set the device/inode. Used to find cycles and check for
633 * crossing mount points. Also remember the link count, used
634 * in fts_build to limit the number of stat calls. It is
635 * understood that these fields are only referenced if fts_info
636 * is set to FTS_D.
637 */
638 dev = p->fts_dev = sbp->st_dev;
639 ino = p->fts_ino = sbp->st_ino;
640 p->fts_nlink = sbp->st_nlink;
641
642 if (ISDOT(p->fts_name))
643 return (FTS_DOT);
644
645 /*
646 * Cycle detection is done by brute force when the directory
647 * is first encountered. If the tree gets deep enough or the
648 * number of symbolic links to directories is high enough,
649 * something faster might be worthwhile.
650 */
651 for (t = p->fts_parent;
652 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)
653 if (ino == t->fts_ino && dev == t->fts_dev) {
654 p->fts_cycle = t;
655 return (FTS_DC);
656 }
657 return (FTS_D);
658 }
659 if (S_ISLNK(sbp->st_mode))
660 return (FTS_SL);
661 if (S_ISREG(sbp->st_mode))
662 return (FTS_F);
663 return (FTS_DEFAULT);
664}
665
666static FTSENT *
667fts_alloc(FTS *sp, const char *name, size_t namelen)
668{
669 FTSENT *p;
670 size_t len;
671
672 len = sizeof(FTSENT) + namelen;
673 if ((p = calloc(1, len)) == NULL)
674 return (NULL);
675
676 p->fts_path = sp->fts_path;
677 p->fts_namelen = namelen;
678 p->fts_instr = FTS_NOINSTR;
679 p->fts_statp = malloc(sizeof(struct stat));
680 if (p->fts_statp == NULL) {
681 free(p);
682 return (NULL);
683 }
684 memcpy(p->fts_name, name, namelen);
685
686 return (p);
687}
688
689static void
690fts_lfree(FTSENT *head)
691{
692 FTSENT *p;
693
694 /* Free a linked list of structures. */
695 while ((p = head)) {
696 head = head->fts_link;
697 free(p);
698 }
699}
700
701/*
702 * Allow essentially unlimited paths; find, rm, ls should all work on any tree.
703 * Most systems will allow creation of paths much longer than PATH_MAX, even
704 * though the kernel won't resolve them. Add the size (not just what's needed)
705 * plus 256 bytes so don't realloc the path 2 bytes at a time.
706 */
707static int
708fts_palloc(FTS *sp, size_t more)
709{
710 char *p;
711
712 /*
713 * Check for possible wraparound.
714 */
715 more += 256;
716 if (sp->fts_pathlen + more < sp->fts_pathlen) {
717 if (sp->fts_path)
718 free(sp->fts_path);
719 sp->fts_path = NULL;
720 errno = ENAMETOOLONG;
721 return (1);
722 }
723 sp->fts_pathlen += more;
724 p = realloc(sp->fts_path, sp->fts_pathlen);
725 if (p == NULL) {
726 if (sp->fts_path)
727 free(sp->fts_path);
728 sp->fts_path = NULL;
729 return (1);
730 }
731 sp->fts_path = p;
732 return (0);
733}
734
735/*
736 * When the path is realloc'd, have to fix all of the pointers in structures
737 * already returned.
738 */
739static void
740fts_padjust(FTS *sp, FTSENT *head)
741{
742 FTSENT *p;
743 char *addr = sp->fts_path;
744
745#define ADJUST(p) { \
746 if ((p)->fts_accpath != (p)->fts_name) { \
747 (p)->fts_accpath = \
748 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \
749 } \
750 (p)->fts_path = addr; \
751}
752 /* Adjust the current set of children. */
753 for (p = sp->fts_child; p; p = p->fts_link)
754 ADJUST(p);
755
756 /* Adjust the rest of the tree, including the current level. */
757 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) {
758 ADJUST(p);
759 p = p->fts_link ? p->fts_link : p->fts_parent;
760 }
761}
762
763static size_t
764fts_maxarglen(char * const *argv)
765{
766 size_t len, max;
767
768 for (max = 0; *argv; ++argv)
769 if ((len = strlen(*argv)) > max)
770 max = len;
771 return (max + 1);
772}
773
774/*
775 * Change to dir specified by fd or p->fts_accpath without getting
776 * tricked by someone changing the world out from underneath us.
777 * Assumes p->fts_dev and p->fts_ino are filled in.
778 */
779static int
780fts_safe_changedir(FTS *sp, FTSENT *p, int fd, const char *path)
781{
782 int ret, oerrno, newfd;
783 struct stat sb;
784
785 newfd = fd;
786 if (ISSET(FTS_NOCHDIR))
787 return (0);
788 if (fd < 0 && (newfd = open(path, O_RDONLY|O_DIRECTORY|O_CLOEXEC)) < 0)
789 return (-1);
790 if (fstat(newfd, &sb)) {
791 ret = -1;
792 goto bail;
793 }
794 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) {
795 errno = ENOENT; /* disinformation */
796 ret = -1;
797 goto bail;
798 }
799 ret = fchdir(newfd);
800bail:
801 oerrno = errno;
802 if (fd < 0)
803 (void)close(newfd);
804 errno = oerrno;
805 return (ret);
806}
807
808#endif
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